Butterfly Populations Down by 20 Percent!! But It Doesn’t Have To Be!!

The title of this post was a recent headline in the news. The release of a recent study shows that since the year 2000, butterfly populations throughout North America have declined by twenty percent. Study Finds That US Butterfly Populations Are Severely Declining | Xerces Society

The study looked at a variety of butterflies, whereas historically the alarm bells have only sounded regarding monarch butterflies. The study also looked at a variety of regions. I suggest you visit the website above and download not only the article but the supplemental materials as well. The supplemental materials give far more information regarding the methodology than the article itself.

While this declining trend is certainly concerning, we should not consider it a lost cause or a sky-is-falling scenario. The trend can be reversed! At Butterfly Ridge, we started keeping data on our butterfly population in 2015. We do this via monthly transects (in late 2024 we switched to twice monthly transects). The transects happen during the first week of each month, on a day that the weather will be most conducive for butterfly activity. No point in doing a transect on a cold, cloudy day. We walk certain sections of our trail and document every butterfly we see that is within 20 feet of the trail. We record information on a datasheet which eventually (within a day or two) gets transferred on to a spreadsheet. By the way, we will share this spreadsheet with anybody who has interest. The following graph is what our data indicates.

The data above represents the total number of butterflies documented on the monthly transects for a given year. As you can see, the population steadily grew between 2015 and 2019. The population has then leveled off for the most part for the past five years. You will note a couple dips in that leveling in 2020 and 2024.

Even the strongest efforts to restore populations can face set backs when weather does not cooperate. In 2020, April and May were abnormally cold in southeast Ohio. The early transects in that year performed horribly. The butterfly population did not return to normal levels until August. In 2024, the early transects were phenomenal. We recorded the best April and May transects ever (thanks in large part to a lack of a winter). And then the drought set in, which lasted for the remainder of the year. The butterfly population crashed hard during the summer months. At Butterfly Ridge, our trees were showing autumn colors early in August, rather than the normal middle of October. The graph below displays monthly transect numbers over time. The yellow bar is 2020, the dashed blue bar is 2024.

The fact remains however, that while the rest of the country has shown a tanking butterfly population, at Butterfly Ridge the population has grown during that same period. This rules out any conditions that the entire country would be facing, long-term weather trends for example.

The reason the Butterfly Ridge population has grown is the land management techniques deployed. At Butterfly Ridge we do not engage in annual mowing of our fields (prairies). Our prairies get mowed at most every three years. We do not mow the entire prairie at once; instead we mow only a third at a time. The same holds true with our woodland openings that we have created. They get mowed, at the most, once every three years, and once again, they don’t all get mowed at the same time.

We have planted a variety of nectar and host plants on the property, to supplement what is already here. Our property is blessed with a lot of tuliptree, black locust, sassafras, and oak. But, the property had those trees long before we started collecting data in 2015. The change we made was to enhance the nectar offerings for tree hosting butterflies like Tiger Swallowtail, Spicebush Swallowtail, Silver-spotted Skipper, and various hairstreaks.

The grasses we planted in our prairie, including Indian Grass, Big Bluestem, Little Bluestem, and Side-oats Grama, have all provided caterpillar food for Common Wood Nymph and various grass skippers. The bush clovers, false indigos, and tick trefoils have provided food for cloudywings and duskywings.

What we have done at Butterfly Ridge is not rocket science. We just view land management a little differently. We have also discontinued the traditional land management methods that have been practiced in our area for generations; management techniques that were more agricultural in nature, like mowing fields in the fall for hay, even though you're not harvesting hay anymore.

The point I am trying to make is that while populations may be down nationwide, it doesn’t have to be that way. And while conservation organizations will be asking you to donate money to help halt the decline, Butterfly Ridge will not be doing that. Donating money to them (or us) will not fix the problem, because afterall, many of you have already been doing that. Instead, what Butterfly Ridge asks, is that you come visit us (yes, there is a $6 admission fee), steal our ideas, take our free seeds, then go home and make a difference in your own yards and communities. This problem will not be solved at the corporate level; it will be solved at the grassroots level. Make your own yard more appealing to butterflies. Then show your neighbor and convince them to do the same. And so on, and so on, and so on, and so . . .